Fuel cell coolant flowfield configuration

Abstract

An exemplary method of cooling a fuel cell includes directing coolant through a coolant supply channel near at least one reactant flow channel. The coolant supply channel extends from a coolant inlet spaced from a reactant inlet to a coolant outlet. The coolant supply channel includes a first portion starting at the coolant inlet and a second portion near the reactant inlet. The first portion facilitates coolant flow from the coolant inlet directly toward the second portion. The second portion includes a plurality of channel sections that collectively facilitate coolant flow in a plurality of directions along the second portion near the reactant inlet. The coolant supply channel includes a third portion between the second portion and the coolant outlet.

We claim: 
     
       1. A fuel cell assembly, comprising:
 a first electrode; 
 a second electrode; 
 a membrane between the first electrode and the second electrode; and 
 a fluid distribution plate having at least one reactant flow channel extending from a reactant inlet located at a first end of the fluid distribution plate to a reactant outlet located at the first end of the fluid distribution plate such that the reactant flow channel forms a two-pass flow pattern between the reactant inlet and the reactant outlet; 
 the fluid distribution plate having a coolant flow field including at least a first coolant supply channel, a second coolant supply channel, and a third coolant supply channel, the first, second, and third coolant supply channels extending from a coolant inlet located at a first side of the plate and spaced from the reactant inlet to a coolant outlet located at a second side of the plate opposite to the first side of the plate across a width of the plate, the first coolant supply channel having a first portion between the coolant inlet and a second portion near the reactant inlet, the first portion facilitating coolant flow from the coolant inlet directly toward the second portion, the second portion comprising a plurality of channel sections that collectively facilitate coolant flow in a plurality of directions along the second portion near the reactant inlet, the first coolant supply channel having a third portion between the second portion and the coolant outlet, the first coolant supply channel extending in a first serpentine pattern adjacent to the second side of the plate near the reactant inlet, the second coolant supply channel extending in a second serpentine pattern adjacent to the first side of the plate, and the third coolant supply channel extending in a third serpentine pattern at a middle region of the plate between the first serpentine pattern and the second serpentine pattern; 
 wherein the first, second, and third serpentine patterns extend back and forth between opposing ends of the plate across a length of the plate perpendicular to the width of the plate; and 
 wherein the coolant flow field is rotationally symmetric about a line perpendicular to a major surface of the fluid distribution plate. 
 
     
     
       2. The fuel cell assembly of  claim 1 , wherein the first portion has a single channel portion that directs the coolant flow in a single direction from the coolant inlet directly to a first one of the channel sections of the second portion. 
     
     
       3. The fuel cell assembly of  claim 1 , wherein the fluid distribution plate comprises a porous water transport plate. 
     
     
       4. The fuel cell assembly of  claim 3 , wherein the water transport plate is micro-porous and hydrophilic. 
     
     
       5. The fuel cell assembly of  claim 1  wherein the width of the plate is shorter than the length of the plate. 
     
     
       6. The fuel cell assembly of  claim 1  wherein the first, second, and third coolant supply channels enter the plate in a direction extending away from the first side of the plate toward the second side of the plate. 
     
     
       7. The fuel cell assembly of  claim 1  wherein the reactant flow channel is a cathode reactant flow channel. 
     
     
       8. The fuel cell assembly of  claim 1  wherein the reactant inlet is coupled to a source of oxygen. 
     
     
       9. The fuel cell assembly of  claim 1  wherein the fluid distribution plate is a first fluid distribution plate, the reactant flow channel is a first reactant flow channel, the reactant inlet is a first reactant inlet, and the reactant outlet is a first reactant outlet, and the fuel cell assembly further comprises a second fluid distribution plate having a second reactant flow channel extending from a second reactant inlet located at a first side of the second fluid distribution plate corresponding to the first side of the first fluid distribution plate to a second reactant outlet located at the first side of the second fluid distribution plate corresponding to the first side of the first fluid distribution plate such that the second reactant flow channel forms a two-pass flow pattern between the second reactant inlet and the second reactant outlet.